62 PLATE XXIV. 



sent to me by Mrs. Gritiitlis in MS. long before I was 

 acquainted with tlie s]3ecimens of Microciona carnosa, 

 vol, ii, p. 133, Mon. Brit. Spongiadas, wHcla I subse- 

 quently found at Sennen Cove, and it was not until I 

 re-examined the British species of Hymeniacidon for 

 figuring in the present volume that I detected the 

 error I had fallen into in my early descriiotion of the 

 specimens sent to me by Mrs. Clriffiths ; and as Mon- 

 tagu's, specific name of plumosa has precedence of that 

 of carnosa, the species must hereafter be designated 

 Microciona plumosa ; the description of the sponge 

 under the desio-nation of M. carnosa beino- received as 



o o 



that of M. plumosa. 



The general aspect of the species is so different in 

 its living state to what it is in its dried condition, that 

 when I found it alive at Sennen Cove I am not sur- 

 prised that I did not recognise it as the same as the 

 dried sponges sent to me by Mrs. Griffiths, and I 

 accordingly described it at that time without reference 

 to those specimens. 



Fig. 7. — A specimen of M. plumosa from Guernsey by 

 the Rev. A. M. Norman. Natural size. From the 

 dried specimen. 



Fig. 8. — The type-specimen from Sennen Cove, 

 Land's End, Cornwall. Natural size, in the dried 

 state. 



Fig. 9. — A fusiformi-a cerate spiculum, from the 

 dermal membrane. X 250 linear. 



Fig. 10. — One of the sub-attenuato-acuate, skeleton 

 spicula, entirely spined. X 250 linear. 



Fig. 11. — One of the internal, defensive, attenuato- 

 acuate, entirely spined spicula. X 250 linear. 



Fig. 12. — One of the bidentate angulated equi-an- 

 chorate, retentive spicula, from the interstitial mem- 

 branes. X 1250 linear. 



Fig. 13. — Represents a small portion of one of the 

 long, slender, and flexuous columns of the skeleton of 

 M. plninosa. X 150 linear. 



This species presents a great variety in its aspect. 



